Removed power_all/enable/disable, useless. Added a multiples of the wakeup.

examples/pingpair_sleepy/pingpair_sleepy.pde

@@ -70,6 +70,9 @@ typedef enum { wdt_16ms = 0, wdt_32ms, wdt_64ms, wdt_128ms, wdt_250ms, wdt_500ms
 void setup_watchdog(uint8_t prescalar);
 void do_sleep(void);
 
+const short sleep_cycles_per_transmission = 4;
+volatile short sleep_cycles_remaining = sleep_cycles_per_transmission;
+
 //
 // Normal operation
 //
@@ -106,7 +109,7 @@ void setup(void)
 
   // Only the ping out role sleeps.  Wake up every 4s to send a ping
   if ( role == role_ping_out )
-    setup_watchdog(wdt_4s);
+    setup_watchdog(wdt_1s);
 
   //
   // Setup and configure rf radio
@@ -192,13 +195,19 @@ void loop(void)
     // Shut down the system
     //
 
+    // Experiment with some delay here to see if it has an effect
+    delay(500);
+
     // Power down the radio.  Note that the radio will get powered back up
     // on the next write() call.
     radio.powerDown();
 
     // Sleep the MCU.  The watchdog timer will awaken in a short while, and
     // continue execution here.
-    do_sleep();
+    while( sleep_cycles_remaining )
+      do_sleep();
+    
+    sleep_cycles_remaining = sleep_cycles_per_transmission;
   }
   
   //
@@ -242,10 +251,9 @@ void loop(void)
 // Sleep helpers 
 //
 
-// 0=16ms, 1=32ms,2=64ms,3=128ms,4=250ms,5=500ms
+// 0=16ms, 1=32ms,2=64ms,3=125ms,4=250ms,5=500ms
 // 6=1 sec,7=2 sec, 8=4 sec, 9= 8sec
 
-
 void setup_watchdog(uint8_t prescalar) 
 {
     prescalar = min(9,prescalar);
@@ -258,8 +266,8 @@ void setup_watchdog(uint8_t prescalar)
     WDTCSR = _BV(WDCE) | wdtcsr | _BV(WDIE);
 }
 
-// Even though it does nothing, it's necessary to have a WDT ISR
 ISR(WDT_vect) {
+  --sleep_cycles_remaining;
 }
 
 void do_sleep(void)
@@ -267,12 +275,9 @@ void do_sleep(void)
     set_sleep_mode(SLEEP_MODE_PWR_DOWN); // sleep mode is set here
     sleep_enable();
 
-    power_all_disable();
     sleep_mode();                        // System sleeps here
 
     sleep_disable();                     // System continues execution here when watchdog timed out 
-    power_all_enable();
 }
 
-
 // vim:ai:cin:sts=2 sw=2 ft=cpp